OCG Rulings

The effect "When you draw this card, if you have no other cards in your hand: You can reveal this card; Special Summon this card from your hand." is a Trigger Effect that activates in the hand. (It does not target. Revealing the drawn "Infernity Archfiend" is a cost to activate this effect.)[1]

The effect "Special Summon this card from your hand." can be activated even during the Damage Step.[1]

The effect "When this card is Special Summoned: You can add 1 "Infernity" card from your Deck to your hand. You must have no cards in your hand to activate and to resolve this effect." is a Trigger Effect that activates on the field. (It does not target.)[1]

The effect "You can add 1 "Infernity" card from your Deck to your hand." can be activated even during the Damage Step.[1]

Even if you draw multiple "Infernity Archfiends" with the effect of "Pot of Greed", etc. while you have 0 cards in your hand, you can only activate the effect of 1 "Infernity Archfiend" to Special Summon itself.[2]